1. Field of the Invention
The present invention is directed to ocular iontophoretic apparatuses, and more particularly, to an ocular iontophoretic apparatus having an improved seal about the surface of the eye and configured for positioning about the sclera.
2. Background Art
The use of ocular iontophoretic devices has been known in the art. Such devices have been used in an attempt to administer a drug through an electromotive force which drives ionic chemicals into and through the eye tissue so that they can be absorbed at the site or, by adjacent tissues and by blood vessels.
Among other problems, difficulties can be incurred with the placement of these devices onto the surface of the eye of a patient. Certain prior art devices encompass a large portion of the eye and cover or interface with the cornea. Specifically, due to the cumbersome nature of these prior art devices and their limited ability to specifically define the placement, treatment site and sharply defined region of of medicament exposure, such devices greatly obstruct vision and the natural movements of the eye during treatment.
Other solutions provide inadequate sealing of the device on the surface of the eye of the patient. As such, current which is used to drive the medicament through the sclera can instead undesirably be conducted via the saline ionic tear fluid of the eye along the surface of the eye and other undesirable tissues. Further, such inadequate seals permit the ingress of tears into the medicament reservoir itself, and adversely contaminates the specific ionically charged drug solution with sodium and chloride ions.
Accordingly, it is an object of the invention to provide an ocular iontophoretic apparatus which provides improved comfort for the user.
It is likewise an object of the invention to provide an improved barrier to seal and preclude the passage of fluid thereacross.
It is another object of the invention to minimize the electrical current from inadvertent and excess shunting via surrounding tear film interference.
These and other objects of the invention will become apparent in light of the specification and claims appended hereto.
The invention comprises an ocular iontophoretic apparatus. The ocular iontophoretic apparatus includes a reservoir having an outer rim. The outer rim includes a barrier which is positionable upon the surface of the eye. The barrier provides a seal between the reservoir and the surface of the eye, to, in turn, substantially preclude the passage of fluid into and out of the barrier.
In a preferred embodiment, the barrier includes means for forming a vacuum/suction seal with a surface of the eye. In one such embodiment, the barrier comprises a first lobe and a second lobe. The two lobes extend away from each other at a predetermined angle. In another such preferred embodiment, the barrier comprises a contact region having a concave configuration.
In a preferred embodiment, a portion of the barrier comprises a material having a Shore A hardness ranging between 5 and 60, and preferably between 5 and 25 to, in turn, provide a substantially fluid tight seal between the barrier and the surface of the eye.
In another preferred embodiment, the barrier includes a first region and a second region. The second region comprises a material having a greater hardness than that of the first region. In one such preferred embodiment, the second region comprises a hardness which may be up to 90 Shore A as well as extend beyond that of Shore A scale 15.
In yet another preferred embodiment, the cross-sectional configuration of the barrier comprises one of the group consisting of: circular, squared, oval, elliptical, asymmetrical and arcuate.
In a preferred embodiment, the outer rim is configured so as to follow the contours of a particular region of the sciera of an eye, to in turn, facilitate the uniform contact of the barrier against the surface thereof. In one such embodiment, the outer rim includes at least a double arcuate configuration, to, in turn, facilitate the uniform contact of the barrier against the surface of an eye. Preferably, the first arcuate configuration includes a radius of curvature which ranges between 10 and 14 mm, and the second arcuate configuration includes a radius of curvature which ranges between 10 and 14 mm.
In a preferred embodiment, the apparatus further comprises a first means for vacuum sealing the reservoir against the surface of an eye of a patient. In one embodiment, the first vacuum sealing means comprises the cooperation of the barrier member and the seal member to facilitate the egress of a quantity of material from within the reservoir, while substantially precluding the ingress of material into the reservoir. In another embodiment, the first vacuum sealing means further includes a valve capable of selectively placing the reservoir in fluid communication with ambient surrounding conditions.
The invention likewise comprises an ocular iontophoretic apparatus which comprises a reservoir having an outer shell. The outer shell includes a transverse radius of curvature to facilitate placement of the apparatus on the sclera of an eye, while substantially precluding contact thereof with the cornea of an eye.
In one preferred embodiment, the transverse radius of curvature which is at least 6 mm.
In another preferred embodiment, the apparatus includes an outer rim. The outer rim includes at least a double arcuate configuration. Such a configuration facilitates the uniform contact of the barrier against the surface of an eye. In one such embodiment, the first arcuate configuration includes a radius of curvature which ranges between 10 and 14 mm, and the second arcuate configuration includes a radius of curvature which ranges between 10 and 14 mm.
The invention likewise comprises a method of sealing an ocular iontophoretic apparatus against the surface of an eye. The method comprises the step of providing an ocular iontophoretic apparatus having an outer rim which includes a barrier having a concave contact region. Once provided, the barrier is positioned so as to engage the concave contact region with the surface of the eye. Next, at least a portion of the air trapped between the concave contact region and the surface of the eye is evacuated which creates a vacuum seal between the surface of the eye and the concave contact region of the barrier.
In one embodiment, the step of positioning the barrier comprises the step of positioning the barrier below the cornea of the eye.
In another embodiment, the method further comprises the step of positioning the eyelid of the patient over at least a portion of the ocular iontophoretic apparatus below the eyelid of the patient.
The invention likewise comprises a method of sealing an ocular iontophoretic apparatus against the surface of an eye. The method comprises the steps of providing an ocular iontophoretic apparatus having a reservoir, an outer rim which includes a barrier, positioning the barrier upon the surface of the eye, evacuating at least a portion of a material from within the reservoir, and, creating a vacuum seal between the surface of the eye and the reservoir.